coder 进阶的专栏

Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. The same repeated number may be chosen from C unlimited numb

Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers. If such arrangement is not possible, it must rearrange it as the lowest possible

Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. Anal

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

Longest Palindromic Substring Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic

Length of last word Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string. If the last word does not exist, ret

1. Valid Parenthese Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the correct order, "()"

1. Length of last word Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string. If the last word does not exist,